Molecular evidence for hybridization between invasive Solidago canadensis and native S. virgaurea

Hybridization between alien and native species is biologically very important and could lead to genetic erosion of native taxa. Solidago × niederederi was discovered over a century ago in Austria and described by Khek as a natural hybrid between the alien (nowadays regarded also as invasive) S. canadensis and native S. virgaurea. Although interspecific hybridization in the genus Solidago is considered to be relatively common, hybrid nature of S. × niederederi has not been independently proven using molecular tools, to date. Because proper identification of the parentage for the hybrid Solidago individuals solely based on morphological features can be misleading, in this paper we report an additive polymorphism pattern expressed in the ITS sequences obtained from individuals representing S. × niederederi, and confirm the previous hypothesis that the parental species of this hybrid are S. canadensis and S. virgaurea. Additionally, based on variability at the cpDNA rpl32-trnL locus, we showed that in natural populations hybridization occurs in both directions

Molecular evidence for the hybrid origin of Potamogeton ×subrufus Hagstr. (Potamogetonaceae)

Potamogeton ×subrufus Hagstr. was described as a hybrid between P. lucens L. and P. nodosus Poir.; however, the taxon had not been widely accepted and regarded as conspecific with P. ×fluitans Roth, the hybrid between P. lucens and P. natans L. The origin of P. ×subrufus had been obscured till 2010, when, based on morpho-anatomical treatment, it was shown that P. ×subrufus displays several characters consistently different from those of P. ×fluitans. Here we report a successful amplification and sequencing of nuclear ribosomal ITS1 region from a 115 year-old herbarium specimen of P. ×subrufus, collected in locus classicus by J. Baagöe and preserved in the Herbarium of the Institute of Botany, Jagiellonian University (KRA). Based on the additive polymorphism pattern expressed in the ITS1 sequences of P. ×subrufus, we demonstrate that one of the parents of this hybrid was P. nodosus, as was claimed by Hagström

Genome size and phenotypic variation of Nymphaea (Nymphaeaceae) species from Eastern Europe and temperate Asia

Despite long-term research, the aquatic genus Nymphaea still possesses major taxonomic challenges. High phenotypic plasticity and possible interspecific hybridization often make it impossible to identify individual specimens. The main aim of this study was to assess phenotypic variation in Nymphaea taxa sampled over a wide area of Eastern Europe and temperate Asia. Samples were identified based on species-specific genome sizes and diagnostic morphological characters for each taxon were then selected. A total of 353 specimens from 32 populations in Poland, Russia and Ukraine were studied, with nine biometric traits being examined. Although some specimens morphologically matched N. ×borealis (a hybrid between N. alba and N. candida) according to published determination keys, only one hybrid individual was revealed based on genome size data. Other specimens with intermediate morphology possessed genome size corresponding to N. alba, N. candida or N. tetragona. This indicates that natural hybridization between N. alba and N. candida is not as frequent as previously suggested. Our results also revealed a considerably higher variation in the studied morphological traits (especially the quantitative ones) in N. alba and N. candida than reported in the literature. A determination key for the investigated Nymphaea species is provided, based on taxonomically-informative morphological characters identified in our study

Evolutionary response of cold-adapted chasmophytic plants to Quaternary climatic oscillaltions in the Mountains of Central Asia (a world hotspot of biodiversity)

Aim Past climatic oscillations are the main driving force of evolutionary changes in alpine species. Species' response to paleoclimatic oscillations is crucial in forecasting their future response in face of climate warming. The aim of this research is to explore the effect of climatic fluctuations on the evolutionary history, demography, and distribution of high-mountain bellflowers (Campanula lehmanniana complex), the flagship and taxonomically problematic members of chasmophytic vegetation within an underexplored biodiversity hotspot, the Mountains of Central Asia. Location Central Asia (Tian Shan, Alai and Zeravshan-Hissar Mountains). Methods We used molecular data (ITS, cpDNA, DArTseq-based SNPs) of 262 individuals (70 for the phylogeny reconstruction, and 247 from 31 localities for population studies). We analysed the data using phylogenetic and molecular clock reconstructions, coalescent simulations, and ecological niche modelling. Results Tertiary isolation between the Tian-Shanian and Pamir-Alaian populations led to the differentiation of the two main lineages (~5-6 Mya) corresponding to C. eugeniae and C. lehmanniana, whereas further Quaternary isolation into subregions led to intraspecific genetic differentiation, which starts almost simultaneously for both species (~2.7-1.5 Mya). The relatively small genetic admixture among populations indicates rare historic events of connectivity. In response to Holocene warming, the analysed species experienced a substantial decline in effective population size. Currently, the distribution of both taxa is highly influenced by precipitation in the coldest and driest quarters. Main Conclusions Our results highlight a general principle that glacial–interglacial cycles and contemporary island-like habitats distribution, shape the genomic variation of high-mountain species. The similar declining demographic trend of examined taxa may suggest the overall response to ongoing climate warming. The results underline also the urgent need for conservation action in alpine regions to preserve their biodiversity

Remarks on Potamogeton hybrids based on characters of P. × salicifolius Wolfg. from a new locality in Poland

Information on Potamogeton hybrids, their identification, taxonomy, ecology and distribution has not been sufficiently recognised yet. Based on characters of P. x salicifolius (= P. perfoliatus x P. lucens) from a new locality in Poland - the Gatno lake (the Kaszuby Lakeland in NW Poland) - general comments on Potamogeton hybrids identification are introduced. The description of P. x salicifolius morphology from the Gatno lake are presented. Analysis of quantitative morphological characters of these specimens provided new information on variability of this taxon. The distribution map of P. x salicifolius in Poland, the original draft of P. x salicifolius based on specimens from the Gatno lake and the table with comparison of P. x salicifolius and the characters of parental species are also provided